Astroviruses were first visualized by electron microscopy (EM) of specimens from infants with gastroenteritis (Madeley et al., Lancet 2:451-452 (1975). Since that time, there have been several reports of infantile gastroenteritis due to astroviruses (Kurtz et al., J. Clin. Pathol. 30:94814 952 (1977); Madeley et al., J. Hyg. (Lond) 78:261-273 (1977); Ashley et al., J. Clin. Pathol. 31:939-943 (1978); Konno et al., J. Med. Virol. 9:11-17 (1982)). Infections in adults have also been reported and there have been suggestions that these viruses have been involved in food and water-borne outbreaks of gastroenteritis (Kurtz et al., Ciba Found. Symp. 128:92-107 (1987).
In most studies, EM of stool samples has been the sole means of establishing the diagnosis of astrovirus infection. Kurtz and co-workers (Kurtz et al., J. Gen. Virol. 57:421-421 (1981) reported serial cultivation of the virus and later determined that five astrovirus types could be distinguished by serological methods (Kurtz et al., Lancet 2:1405 (1984).
The true incidence of astrovirus infection has been difficult to establish because of the lack of convenient and efficacious identification and detection techniques. Diagnostic techniques using EM for observing the presence or absence of an astrovirus in a biological sample are labor-intensive and are not always reliable due to the risk of human error. According to Kurtz and co-workers, (Kurtz et al., Lancet 2:1405 (1984) astrovirus antisera is type specific. Therefore, an antiserum against one strain of astrovirus may not be capable of detecting a different strain of astrovirus.